Apparatus and composition for sharpening a paper shredder blade, and preparation process therefor

ABSTRACT

Composition, apparatus, and methods of composition and apparatus manufacture, for sharpening a paper shredder blade. Composition includes grinding powder, thickening agent, and additive. The thickening agent may be a white oil, an animal oil, an vegetable oil, or a stearine wax. The additive may be an antirust powder, an antiwear powder, an antistatic powder, or an antioxidation powder. The grinding composition is dispensed into a polyethylene film, and sealed to form the grinding apparatus, as a grinding sheet or a grinding packet. A method for forming a grinding sheet includes selecting the constituent materials for a grinding composition; stirring the constituent grinding composition materials; heating the constituent materials to melting; mixing the constituent materials, while melting and intermixing; cooling and packaging the grinding composition to form a grinding sheet or packet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of and claims benefit tocopending application Ser. No. 12/837,377, filed Jul. 15, 2010, entitled“APPARATUS AND COMPOSITION FOR SHARPENING A PAPER SHREDDER BLADE, ANDPREPARATION PROCESS THEREFOR,” assigned to the same Assignee hereof, andto application Attorney's Docket No. A027-8043-US, filed on Apr. 12,2013, and entitled “APPARATUS AND COMPOSITION FOR SHARPENING A PAPERSHREDDER BLADE, AND PREPARATION PROCESS THEREFOR,” assigned to the sameAssignee hereof, which both are incorporated herein in their entirety.The aforementioned applications claim priority to China Application,Ser. No. 200910056439.5, filed Aug. 14, 2009.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to the technical field of paper shredders,and in particular, the paper shredder maintenance.

2. Background Art

The main element of a current paper shredder is a paper shredder corewherein two sets of paper shredder blades are mounted. The two sets arerotated in opposite directions when shredding papers. Under cooperationof the two sets of paper shredder blades, paper to be shredded isdestroyed when sent into the paper shredder. However, the paper shredderblades will lose sharpness over time, which reduces the shredding effectand may lead to paper shredder malfunctions, such as paper jams. Inextreme cases, the shredder blades will be damaged, degrading the normalshredder operation, and even causing paper shredder breakdown.

A conventional method to solve the above problem is to disassemble thepaper shredder, to take down the blades of the paper shredder bladesets, to grind the blade sets for resharpening, and then to reassemblethe paper shredder. However, this method interrupts shredder use and maytake significant time and effort. Another method is to directly changethe sets of paper shredder blades, which takes less time than thepreceding method, but increases the maintenance cost. This alternativemethod is still troublesome, because the paper shredder is typicallydisassembled during maintenance. Many end users will not, or do not wishto, disassemble a shredder for repair; as a result, many such users cometo accept declining shredder performance over time.

It is desirable, then, to provide a grinding composition and apparatusfor sharpening a paper shredder blade, as well as a preparation processtherefore, suitable to resolve the aforementioned problems.

SUMMARY OF THE INVENTION

Described herein are example embodiments of grinding compositions forsharpening a blade of a paper shredder, grinding apparatus that caninclude the grinding composition, methods for preparing embodiments ofthe grinding composition, and methods for preparing embodiments of thegrinding apparatus.

In embodiments of a grinding composition for sharpening a blade of apaper shredder, there can be included a selected grinding powder in aconcentration of between about 51% w/w to about 65% w/w, a selectedthickening agent in a concentration of between about 5% w/w to about 35%w/w, and a selected additive in a concentration of between about 3% w/wto about 30% w/w. The selected grinding power can have a particle sizeof between about 0.1 microns to about 40 microns.

The selected thickening agent can be one or more of a white oil, ananimal oil, an vegetable oil, or a stearine wax. The additive can beselected from one or more of an antirust powder, an antiwear powder, anantistatic powder, or an antioxidation powder. An antirust powderadditive can be a stearate powder, such as aluminum distearate. Anantiwear powder additive can be a microcrystalline wax, or a complexsodium-calcium based soap grease powder. An antistatic powder additivecan be a glycerol monostearate powder An antioxidation powder additivecan be a dibutyl-hydroxytoluene (butylated hydroxytoluene) powder.

First example embodiments of the grinding composition may have aselected grinding powder concentration of about 55% w/w, the selectedthickening agent concentration of about 35% w/w, a selected antirustpowder additive concentration of about 5% w/w, a selected antiwearpowder additive concentration of about 2% w/w, a selected antistaticpowder additive concentration of about 2% w/w, and a selectedantioxidation powder additive concentration of about 1% w/w. Firstexample embodiments can have one of a white oil or a vegetable oil as athickening agent.

Also, second example embodiments of the grinding composition can have aselected grinding powder concentration of about 57% w/w, a selectedthickening agent can have a concentration is about 35% w/w, a selectedantirust powder additive can have a concentration of about 5% w/w, aselected antistatic powder additive can have a concentration of about 2%w/w, and a selected antioxidation powder additive can have aconcentration of about 1% w/w. Second example embodiments may employ astearine wax as a thickening agent. Also, second example embodiments canuse a natural mineral grinding powder as a selected grinding powder,aluminum distearate powder as a selected antirust powder additive,glycerol monostearate powder as a selected antistatic powder additive,dibutyl-hydroxytoluene powder as a selected antioxidation powderadditive, and one of a microcrystalline wax or a complex sodium-calciumbased soap grease powder as a selected antiwear powder additive. Inaddition, the stearine wax can be prepared by combining stearic acidwith one or more of a white wax, a microcrystalline wax, and apolyethylene wax. Moreover, in some of the second example embodiments,the stearic acid can be prepared from an animal fat and a vegetable fat.

In addition, in selected embodiments where the selected grinding powderis natural mineral grinding powder, the selected grinding powder can beone of a grinding powder of natural diamond, or a grinding and polishingpowder of natural micron quartz.

In first example embodiments of the grinding apparatus, the apparatuscan include a selected grinding powder constituent in a concentration ofbetween about 51% w/w to about 65% w/w, a selected thickening agentconstituent in a concentration of between about 5% w/w to about 35% w/w,and a selected additive constituent in a concentration of between about3% w/w to about 30% w/w. First example embodiments can be formed into agrinding sheet, so that the grinding sheet is shredded by the blade ofthe paper shredder, so that the shredder blade can be sharpened byshredding the grinding sheet.

In a first example embodiment for preparing a grinding apparatus, aprocess includes selecting a selected grinding powder constituent in aconcentration of between about 51% w/w to about 65% w/w, selecting aselected thickening agent constituent in a concentration of betweenabout 5% w/w to about 35% w/w, and selecting a selected additiveconstituent in a concentration of between about 3% w/w to about 30% w/w.As with previous embodiments the selected grinding powder may be betweenabout 0.1 micron to about 40 microns. In certain selected embodiments,the selected thickening agent can be a stearine wax. The process cancontinue by stirring the constituents, melting the constituents, andintermixing the constituents until homogenized into a grindingcomposition. After the grinding composition is formed, the process cancontinue by cooling the grinding composition; and packaging the grindingcomposition into a preselected form. The preselected form can be one ofa grinding sheet or a grinding packet.

In an example embodiment in which the preselected form can be a sheet,the process embodiment also can continue by compressing the grindingcomposition into a grinding sheet, and, in some grinding sheetembodiments, also can include cutting the compressed grindingcomposition into sheets having one or more of a preselected width, apreselected length, and a preselected thickness. Alternatively, inanother example embodiment in which the preselected form can be apacket, the process embodiment can continue by depositing the grindingcomposition into a plastic bag, and sealing the plastic bag.

In yet another example embodiment in which the preselected form can be apacket, the process can include pre-measuring a volumetric bolus of thegrinding, and enwrapping the volumetric bolus in a portion of a wrapper.The wrapper may be a plastic bag or a portion of a plastic sheet.Furthermore, sealing the plastic around the volumetric bolus can form asealed grinding packet. The plastic bag or the portion of a plasticsheet can be made of polypropylene.

In some embodiments of a process for making a grinding apparatus, priorto enwrapping, the grinding composition into a preselected form, theprocess for making a grinding apparatus can include imposing an image onone of the roll of plastic film or the plastic bag. The image can be oneof a character, a picture, or a symbol. In alternative embodiments,imposing the image can be implemented by imposing the image by singlecolor printing or imposing the image by chromatography.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiment of the present invention disclosed herein are illustrated byway of example, and are not limited by the accompanying figures, inwhich like references indicate similar elements, and in which:

FIG. 1 is an exploded perspective view of a grinding apparatus forsharpening a paper shredder blade, in accordance with the teachings ofthe present invention;

FIG. 2 is a plan cross-section view of a grinding apparatus forsharpening a paper shredder blade, in accordance with the teachings ofthe present invention;

FIG. 3A is a flow chart illustrating a method for preparing a grindingapparatus for sharpening a paper shredder blade, in accordance with theteachings of the present invention; and

FIG. 3B is a flow chart supplementing the flow chart in FIG. 3Aillustrating a method for packaging a grinding apparatus for sharpeninga paper shredder blade, in accordance with the teachings of the presentinvention.

Skilled artisans can appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions of some of the elements inthe figures may be exaggerated relative to other elements to helpimprove the understanding of the embodiments of the present invention.

DESCRIPTION OF THE EMBODIMENTS

The embodiments herein provide examples of apparatus, compositions, andprocesses for preparing the compositions, that can be used to sharpenthe blades of a paper shredder and that can be prepared in astraightforward manner using widely available raw materials, in light ofthe teachings herein. The apparatus may be, without limitation, in theform a grinding sheet or a grinding packet: (1) which can contain anembodiment of a grinding composition described herein; (2) which cangrind and sharpen the paper shredder blades safely and effectively; or(3) which are easy to manage and use, without shredder disassembly bythe shredder user. A preferred embodiment of the apparatus may exhibitall three characteristics.

Application of a grinding apparatus, or grinding composition, or both,to a paper shredder in accordance with the present disclosure can beuseful in maintaining good shredder performance and an extending servicelife, thus reducing costs. Because the shredder apparatus embodimentsherein can be safe and easy to use, the embodiments can be suitable forwidespread use, for example, in homes and in business offices.

Grinding composition embodiments of the present invention providegrinding compositions for sharpening a paper shredder blade, each ofwhich compositions can include preselected concentration of a selectedgrinding power; a preselected concentration of a selected thickener; anda preselected concentration of a selected additive. More than oneadditive may be used. A suitable selected additive can be one or more ofthe group consisting of a selected antirust powder, a selected antiwearpowder, a selected antistatic powder, or a selected antioxidationpowder.

The grinding composition may be applied to grind and to keep sharp thepaper shredder blade, and to remove shredder blade surface soilingincluding, without limitation, removing rust spots, minimizing bladestains, removing paper debris, and generally restoring the surface ofthe blades of the paper shredder. The grinding apparatus can be in theform of a grinding sheet, or a grinding packet. In accordance with abenefit of the present embodiments, it becomes unnecessary to open thepaper shredder or to disassemble the shredder blade mechanism, to grindsharp the paper shredder blades. Both the grinding sheet and thegrinding packet can be introduced directly to the paper shredder bladesthrough the paper shredder feed opening. In certain ones of embodiments,when the shredder blade shreds a grinding packet having therein agrinding composition for sharpening a paper shredder blade, as in theusual paper shredding process, the sealed bag of the grinding packet iscut open, and the grinding composition therein contacts, grinds, andsharpens the blade. Functional additives to the grinding composition canimpart other desirable characteristics onto the shredder blade. Incertain others of embodiments, when the shredder blade shreds a grindingsheet for sharpening a paper shredder blade, as in the usual papershredding process, the grinding sheet is shredded and the grinding sheetgrinding composition constituents therein contact, grind, and sharpenthe shredder blade. Functional additives to the grinding composition canimpart other desirable characteristics onto the shredder blade.

As used herein, a grinding material is an abrasive mineral material(equally, an abrasive material, or an “abrasive”), which can have amineral hardness of between about 7 to about 10 on the Mohs scale.Typically, very hard materials, for example, scoring between about 9 toabout 10 on the Moh's scale, can include without limitation, corundum(Al₂O₃), or silicon carbide (SiC), but can be costlier than naturalquartz, natural micron diamond, or a commercial combination of naturalquartz and natural micron diamond. A grinding powder can be constitutedof one or more grinding materials. Preferably, a grinding powder is agrinding material having a particle size of between about 0.1 micron toabout 40 microns, although larger particle sizes, for example, up toabout 70 microns, also may be used. In addition, a suitable grindingpowder can have a hardness of between about 7 to about 10 on the MohsHardness scale (“Mohs” or “Mohs scale”). Typically, quartz grindingpowder has a hardness of about 7 Mohs.

Abrasive materials used in accordance with the teachings of the presentinvention are hard, non-metallic materials, which can be generallycategorized as a natural abrasive or as a man-made (synthetic) abrasive.Non-limiting examples of natural abrasives can include natural steelgrit, natural corundum, natural diamond (diamond), natural quartz,garnet, flint, pumice, bacillariophyceae, or diatomaceous, earth, talc,gypsum, feldspar, chert, chalk, river sand, sea sand, atmosilicarenite,apatite, fluorite, calcite, or coal cinder. Because natural resourcesare growing limited, natural abrasives have been relegated to analternative status relative to artificial, or synthetic, abrasives.

Non-limiting examples of artificial or synthetic abrasives can includecorundum, silicon carbide (i.e., carborundum), boron carbide, syntheticdiamond (diamond), cubic boron nitride, alumina, fused mullite, densecorundum, spinel, α-alumina, glass sand, ceramic vermilion, or glassbeads. Non-limiting examples of corundum can include brown fusedalumina, white fused alumina, black fused alumina, alumina corundum,zirconium corundum, chromium corundum, crystal corundum, or corundumceramics. Non-limiting examples of an alumina can include white alumina,brown alumina, or pink alumina. Non-limiting examples of a siliconcarbide can include black silicon carbide or green silicon carbide.

Artificial abrasives can be further divided into two segments: asuper-hard abrasive or a general abrasive. Non-limiting examples ofsuper-hard abrasives can include synthetic diamond (diamond), cubicboron nitride, or boron carbide. Similarly, non-limiting examples ofgeneral abrasives can include a corundum, an alumina, a silicon carbide,fused mullite, dense corundum, spinel, α-alumina, glass beads, glasssand, ceramic cinnabar, or zirconia beads.

For the sake of clarity, the amounts of powder, agent, and additive willbe described in terms of % w/w (by weight) concentration, of thecorresponding constituent, relative to the amount of grindingcomposition being described. In addition, the expression “grindingapparatus” is intended to denote a grinding packet or a grinding sheet,made from a grinding composition, in accordance with the principlesdescribed herein.

A thickening agent can be used (1) to prepare a complex sodium-calciumbased soap grease powder; and (2) to thicken the grease powder topromote cohesion and prevent untimely separation of the grinding powder,from one or more of the antirust powder additive, the antistatic powderadditive or the antioxidation powder additive.

A suitable selected thickening agent can be one or more of the groupconsisting of a white oil, an animal oil, a vegetable oil, a white wax,a microcrystalline wax, a polyethylene (PE) wax, or a stearine wax.Desirably, the stearine wax can be prepared by combining stearic acidwith one or more of a white wax, a microcrystalline wax, or apolyethylene wax (PE wax). The stearic acid can be made from one or bothof an animal or a vegetable fat. Additional suitable thickening agentsalso may be, without limitation, a cosmetic white wax oil, a lightmineral oil, such as “baby oil.” It is desirable that thickening agentsgenerally be fit for human contact, and may be capable of naturaldegradation.

Antistatic powder additive may be applied to remove static, to preventpaper debris, retained powder, or other unwanted matter, from adheringto the paper shredder blades, which may impair the shredding function ofthe blades. Antistatic powder additive also may be applied to reducegeneration of static charges or to effectively dissipate existing staticcharges. The antistatic powder additive can be coated on the surface ofa product or added therein. Antistatic powder additive can reduce therisk of a paper powder dust explosion, which may result from electricalsparks generated by the shredder motor, or from a static charge spark,which may accumulate on the paper shredder enclosure. A suitableantistatic powder additive can be, without limitation, a glycerolmonostearate powder.

Antioxidation powder additive can be applied to inhibit the progress ofoxidation and rusting of the paper shredder blade metal, and can avoidoxidative rancidity of stearine wax if used in the thickening agent.Desirably, the antioxidation powder additive is added prior to the onsetof oxidative rancidity, because the oxidation cannot be substantiallyreduced once the oxidation reaction has occurred. A suitableantioxidation powder additive can be, without limitation, adibutyl-hydroxytoluene (butylated hydroxytoluene) powder.

Antiwear powder additive can be applied to prevent abrasion and bruisingof the metal surface of the paper shredder blades and to reducevibration noise. A suitable antiwear powder additive can be, withoutlimitation, a microcrystalline wax, or a complex sodium-calcium basedsoap grease powder. In general, a wear-resistant molding agent,including without limitation, microcrystalline wax or complexsodium-calcium based soap grease may be applied to adhere to theshredder blade metal surface with good adsorbability and to combine withmicron quartz powder to form a rigid protection film on the shredderblades to prolong blade life. The size of micron quartz powder isnormally more than about 120 mesh, and can be used for polishing. Micronquartz powder is a grinding powder that can be combined thoroughly withother grinding powders in grinding composition including awear-resistant molding agent. In embodiments in which the grindingcomposition is to use between about 51% w/w to about 60% w/w of grindingpowder, the total % w/w concentration of all selected grinding powdersincluding micron quartz powder used is preferred to be about 60% w/w.More the micron quartz powder can be used, although the concentration ofother selected grinding powders in such embodiments would be decreasedby similar measure.

An antirust powder additive can be added to minimize the development ofrust on the paper shredder blade. An antirust protection film can becoated on the paper shredder blade to prevent it from rusting, such thata stationary adhesion film is formed on the metal surface to preventoxygen and water, especially water, from contacting the metal surface toprevent the metal from rusting.

However, common mineral oil or vegetable oil alone tends to exhibit aweak adsorbability to the shredder blade metal surface. Typically, freeradical energy on the metal surface can be in a range of between about0.1 Newton/meter (N/m)) to about 1 N/m. Water has a surface tension of8×10⁻⁴N/cm and the surface tension of a hydrocarbon, such as commonmineral oil or vegetable oil, tends to range from about 2×10⁴N/cm toabout 3×10⁻⁴N/cm. Thus, common mineral oil or vegetable oil may form anunsuitable non-stationary oil film, because of the tendency of theseoils to absorb and dissolve part of water and oxygen to which they maybe exposed, allowing the oil film to be easily permeated. Although thesecommon unmodified oils, alone, may play a weak role as an antirust film,their respective antirust properties are significantly improved by theaddition of an antirust power additive. A suitable selected antirustpowder additive can be, without limitation, a stearate powder, such asaluminum distearate.

FIG. 1 is a cross-sectional front view of grinding sheet 100 (alsocalled a grinding page), which may be formed of a selected grindingcomposition. In general, a grinding composition may be viewed asgrinding powder 2 intermixed in functional matrix 3. Functional matrix 3can include at least one thickening agent, and at least one selectedadditive. Functional matrix 3 can be disposed in a wax-like form, whichmay facilitate economic manufacturing.

FIG. 2 is an exploded perspective view of grinding sheet 200, which maybe similar to grinding sheet 100. Grinding sheet 100 can be formed suchthat plastic sheet 1 may enwraps functional matrix 3, for example, asshown in FIG. 2. Plastic sheet 1 may be provided from a continuous rollof plastic sheet, from a continuous roll of a plastic sleeve, or fromindividual plastic sheeting containers. Furthermore, plastic sheet 1 maybe fabricated from two or more layers, which may be sealed or laminatedtogether. Moreover, grinding packet 200 may be formed by laminating aplastic sheet 1 on opposing surfaces of formed grinding composition 2,3.

The size of the grinding sheet or grinding page may be formed as havinga single page width as measured across a longitudinal aspect of a feedopening of a paper shredder. Grinding sheet length may be, for example,that of a standard Letter or A4 paper sheet, or may be formed to belonger or shorter, as found to be efficacious for a type of papershredder. Alternatively, a width of a grinding sheet relative to alongitudinal aspect of a feed opening may be formed to be wider ornarrower than the respective shredder feed opening.

In embodiments of a grinder sheet in accordance with the foregoingmethod, one constituent grinding composition material can be athickening agent including stearine wax. Those of ordinary skill in theart would readily ascertain the physical parameters involved inproducing a grinding sheet having desired characteristics, in view ofthe above teachings.

Some embodiments of a grinding composition according to the teachingsabove may be constituted of between about 51% w/w to about 65% w/w of aselected grinding powder; between about 5% w/w to about 35% w/w of aselected thickening agent; and between about 3% w/w to about 30% w/w ofa selected additive.

In certain embodiments of a grinding composition, it is desirable toprovide: a grinding powder in the concentration of about 55% w/w, anantirust powder additive in the concentration of about 5% w/w, anantiwear powder additive in the concentration of about 2% w/w, athickening agent in the concentration of about 35% w/w, an antistaticpowder additive in the concentration of about 2% w/w, and anantioxidation powder additive in the concentration of about 1% w/w. Thethickening agent may be constituted of a white oil or a vegetable oil,or both.

In alternative embodiments of a grinding composition, the concentrationof a grinding powder may be about 57% w/w, the concentration of aantirust powder may be about 5% w/w, the concentration of a thickeningagent may be about 35% w/w, the concentration of the antistatic powdermay be about 2% w/w and the concentration of the antioxidation powdermay be about 1% w/w. In these alternative embodiments, the thickeningagent can be stearine wax.

A present method 300 for forming grinding sheet 100, 200 is illustratedin FIGS. 3A-3B, and can include: selecting (310) the constituentmaterials for a grinding composition of a grinding sheet for sharpeninga paper shredder blade; stirring (320) the constituent grindingcomposition materials 2, 3; heating (330) the constituent grindingcomposition materials to effect melting; mixing (340) the constituentgrinding composition materials, while melted to achieve a preselectedintermixing thereof; cooling (350) the intermixed grinding compositionmaterials; and enwrapping (360) the cooled intermixed grindingcomposition constituents to form one of a grinding sheet or a grindingpacket. In some embodiments, such as those in which a grinding sheet isformed, the method also may include one or both of compressing (370) thecooled intermixed grinding composition constituents, for example to forma flat grinding composition sheet, or cutting to size (380) the grindingcomposition sheets to the selected length and selected width. Of course,one of ordinary skill in the art would realize that extremely largesheets could be prepared, cooled, and cut into grinding sheets of adesired, predetermined size.

In certain other embodiments, enwrapping (360) for grinding apparatusfor sharpening a paper shredder blade can include pre-measuring (365) avolumetric bolus of grinding composition into the shape of a packet. Asused herein, the term “volumetric bolus” describes a mass of materialhaving a known volume. Process 300 may continue by forming (375) agrinding packet blank capable of receiving the volumetric bolus from atleast one sheet of plastic film. Formation of the grinding packet cancontinue by enwrapping (385) the volumetric bolus of grindingcomposition within the plastic bag or plastic film, and by sealing (395)the volumetric bolus of grinding composition following enwrapping. Incertain embodiments, a grinding packet can be a plastic sealed bag. Inselected embodiments, a grinding packet can be a polypropylene sealedbag. In certain selected embodiment in which a plastic film is used, theplastic film can be a polypropylene plastic film. Sealing (395) may beeffected, for example, by sealing at least a portion of the respectiveperiphery of two opposite sidewalls of plastic sheeting containingtherein the volumetric bolus of grinding composition. Also, someembodiments of a grinding packet may be formed from a sealable plasticbag. Moreover, a grinding sheet may be disposed in a sealed plastic bag,a sealable plastic bag, or a non-sealed plastic bag.

A present method for forming a grinding packet for sharpening a papershredder blade, such as method 300 in FIGS. 3A-3B can be performed by anautomatic filling machine for making bags, such as, without limitation,an automatic forming, filling, and sealing (FFS) machine. The FFSmachine may have a feed channel for pre-measuring (365) a volumetricbolus of a grinding composition to be deposited on a sheet portionintended to become a grinding packet. Other embodiments of method 300for forming a grinding packet can include: shift positioning (362) aroll of a plastic film on the FFS machine; feeding (364) into a feedchannel of the FFS machine a selected grinding composition forsharpening a paper shredder blade; forming (375) a grinding packet blankhaving the predetermined width and predetermined length; depositing(384) a volumetric bolus of the selected grinding composition into thegrinding packet blank; enwrapping (385) the volumetric bolus with thegrinding packet blank; sealing (395) at least a portion of a peripheryof grinding packet blank containing the volumetric bolus of the selectedgrinding composition held therein; and finishing (398) the filled packetblank to form a sealed grinding packet.

In certain ones of the embodiments of grinding apparatus, thepolypropylene plastic film, or bag, can be made from orientedpolypropylene (OPP), cast polypropylene (CPP), or, desirably, from acombination of OPP and CPP films (e.g., OPP.CPP film). OPP.CPP film,whose main element is polypropylene plastic, is recyclable, can becompletely combusted, does not generate a toxic gas during incineration,and does not degrade the use life of an incinerator, reducing bothsecondary pollution and higher recycling costs.

At least one character, a picture, or a symbol characters and/orpictures can be imposed on the plastic film in advance of forming thegrinding packet using, without limitation, a single-color printingtechnique or a chromatography technique.

In certain embodiments of the method for forming a grinding packet forsharpening a paper shredder blade, preparation of at least a portion ofthe grinding composition can be performed proximate to the FFS machineapproximately simultaneously with the feeding into the feed channel, orthe grinding composition may be pre-mixed and, in some cases, may bepre-measured as a volumetric bolus prior to feeding. In general, therequired filling concentration of the grinding composition forsharpening a paper shredder blade may be adjusted during a grindingpacket forming process, as may the width and length of the finishedplastic package. Those of ordinary skill in the art would realize thathorizontal and vertical types of FFS machines can be used to form thegrinding packets herein, as well as other types of packaging machinery.

Two Example Processes, namely Example Process I and Example Process II,are provided below to further illustrate the principles of producing agrinding composition, in accordance with present teachings.

EXAMPLE PROCESS I

The example first process for preparing a grinding packet for sharpeninga paper shredder blade can be performed in a working environment havinga room temperature between about 20° C. and about 30° C., and having arelative humidity of between about 60% and about 70%.

Example Process I can include making a complex sodium-calcium based soapgrease using an oil mixture, having about 20% grease in the total oilamount, and an alkaline substance, to form a solution in a reactioncontainer. The grease can be composed of animal grease, vegetablegrease, or a combination of animal grease and vegetable grease. Thealkaline substance can be, without limitation, one or more of sodiumhydroxide, calcium hydroxide, or calcium acetate. Mixing the oil mixturewith the alkaline substance can cause hydrolysis of the fats in thegrease and oils to occur, producing glycerol and a soap. This hydrolysisprocess commonly known as a saponification reaction. A saponificationreaction is a slow, exothermic chemical reaction. To optimize andaccelerate the saponification reaction, a relatively high temperature,such as between about 75° C. to about 85° C. may be maintained in thereaction container during the chemical reaction process, and thesolution can be stirred substantially continuously, for example, atbetween about 1,000 revolutions/min to about 1200 r/min, to increase thenumber of molecular collisions between constituents of the solution inthe reaction container.

Referenced saponification values, which are well-known in the art, andsamples of which are shown in TABLE 1, can be helpful when calculatingthe amount of sodium hydroxide required by a grease saponificationreaction.

TABLE 1 Saponification value (sodium Hardness Value Types of Oilhydroxide/NaOH) (INS Value) Olive Oil 0.134 109 Coconut 0.190 258 Palm0.141 145 Rice Bran 0.128 70

Chemical Equation of Saponification Reaction

A chemical formula for triglyceride is:

CH₂COOR—CHCOOR—CH₂—COOR→C₃H₅(OCOR)₃→RCOOR′

A triglyceride can be composed of three molecules of a fatty acid(R—COOH) and one molecule of glycerol (C₃H₅(OH)). Therefore, an equationof the saponification reaction can be:

CH₂COOR—CHCOOR—CH₂—COOR+3 NaOH

3 R—COONa+CH₂OH—CHOH—CH₂OH (glycerol),

wherein

3 R—COONa is a soap base of sodium aliphatate; and

R- can be one of:

-   -   C17H₃₃—: 8-heptadecenyl, in which R—COOH is oleic acid;    -   C₁₅H₃₃—: n-pentadecyl, in which R—COOH is palmitic acid; and    -   C₁₇H₃₅ 13 : heptadecyl, in which R—COOH is stearic acid;

In general, grease is a monounsaturated fatty acid, and can be obtained,for example, by hydrolyzing oil. Palmitic acid and stearic acid are bothsaturated fatty acids, and each may be obtained by hydrolyzing fat.

Application of Saponification Reactant to Grinding Composition

Complex sodium-calcium based soap grease, like a sponge, can absorb alarge amount of grinding powder 2 and remain in a semi-solid state.Sodium-calcium based soap grease exhibits desirable water andtemperature tolerance, and good antiwear properties. The dropping pointof a grease is the temperature at which the grease begins to liquefy andbecomes fluid enough to drip. The dropping point of the complexsodium-calcium based soap grease is at about 150° C.; however, it may beused in a temperature range of between about 100° C. to about 130° C. Byitself, the complex sodium-calcium based soap grease displays strongadsorbability to metal, and can be combined with a micron quartz powderto form an antiwear film on the shredder blade metal.

In general, there can be a positive correlation between theconcentration of the soap grease in the grinding composition and itsthickness. Typically, by increasing the concentration of soap grease,the grinding composition tends to exhibit increasing thickness.Conversely, by decreasing the concentration of soap grease, the grindingcomposition tends to exhibit decreasing thickness. Thus, one techniqueto adjust the thickness of a particular grinding composition is toadjust the concentration of complex sodium-calcium based soap greaseincluded in the grinding composition.

Use of the aforementioned optimized parameters may shortensaponification time to 45 minutes, after which substantially continuousstirring may be performed until the soap cools, for example, to roomtemperature. Of course, a suitable cooling system may be used toaccelerate cooling. One or more thickening additive constituents may beadded to the complex sodium-calcium based soap grease. Suitablethickening additive constituents may include one or more of a white oil,an animal oil, or a vegetable oil. Grinding powder 2 may be intermixeduntil substantially evenly diffused in the complex sodium-calcium basedsoap grease mixture, to obtain a gel in a semi-solid state.

Mixing may be performed using a two-channel mixer, having an A-channeland a B-channel. Grinding powder 2 can be sieved to reduce thelikelihood of the powder deliquescing from contact with ambientmoisture, which may lead to undesirable grinding powder agglomeration.In certain embodiments, complex sodium-calcium based soap grease may beplaced in A-channel and be substantially continuously stirred by astirring machine at a rate of between about 100 r/min. to about 1200r/min. A substantial portion of one or more thickening agents, forexample 80%, may be held in B-channel, while a selected additive 3 is bediffused in B channel. The grease mixture in B-channel may befast-stirred by the stirring machine at a rate of between about 3000r/min and about 4000 r/min to promote substantially complete dissolutionof the selected additive into the B-channel mixture. The grease mixturein B-channel may be added slowly into A-channel and may be substantiallycontinuously stirred until the grease mixture is completely dissolvedinto a paste.

A non-limiting example of the slow adding of B-channel constituent intoA-channel constituent can be adding B-channel constituent at a speed ofabout 10% of the total oil amount per minute into A-channel constituent.Thereafter, grinding powder 2 may be dispersedly added, for example,using substantially continuous stirring, to produce a semi-solid gel.The semi-solid gel in A-channel may be spirally propelled into a feedchannel of an FFS machine for making bags, such that finished grindingpackets are prepared in accordance with the teachings herein.

EXAMPLE PROCESS II

A grinding sheet for sharpening a paper shredder blade can be preparedby a second example process, in which non-limiting example of a suitableworking environment can be characterized, at least in part, by having anambient temperature between about 20° C. to about 30° C. Also, relativehumidity in the working environment can be between about 60% to about70%.

Stearic acid may be made from an animal fat, or by a vegetable fat, orby a suitable combination of animal fat and vegetable fat. The stearicacid may be placed in a single-channel stirring bucket capablebi-directional gear shifted stirring bucket. The stirring bucket may bemaintained at a temperature of about 200° C., using, for example, anadjustable temperature cycling kerosene heater. One or more of a whitewax, a microcrystalline wax, or a PE wax may be mixed into the channel.After wax is substantially completely dissolved in the channel, thebucket temperature may be lowered to about 150° C. and may be stirred ata speed of between about 1000 r/min. to about 1200 r/min. A selectedadditive may be added to the stirring bucket mixture and stirred untildissolved. Previously-sieved grinding powder 2 may be added to thestirring machine bucket, with the stirrer being adjusted to stir themixture at a speed of between about 2000 r/min. to about 2500) r/min.

Approximately 15 minutes later, the stirring pot mixture may bemaintained at a temperature of about 120° C., with the stirring machinebeing adjusted to stir the mixture at a speed of between about 1000r/min. to about 1200 r/min. The mixture may be sent thereafter to acooling system, for example, via a heat-insulated, compressed airtransmission line. The cooling system, if used, may employ cooling watercycling, in which the grinding composition mixture may be deposited on agrooved metal transfer sheet having a surface covered with PTFE. Afterthe mixture is cooled, it may be compressed to a preselected thickness,and may be cut into sheets having a selected width and a selectedlength. A cutter employing a gear shift motor transmission set may beused to cut the grinding composition into wax-like sheets. The solidwax-like grinding composition sheets may be sent to a automatic planingmachine to finish the form of the grinding sheet, for example, to apreselected thickness. One or more formed grinding composition sheetsmay be packaged into a non-sealed bag, or an unsealed bag which may besealable. Grinding composition sheets may be “stacked” in that the morethan one layer of grinding composition sheet may be laminated togetherto achieve, for example, a preselected thickness.

In the above Example Processes I and Example Process II, grindingapparatus 100, 200 (sheet or packet) may be made (400) by: shiftpositioning (410) a roll of laminated plastic film on an automaticfilling and bagging machine; feeding (420) a grinding composition forsharpening a paper shredder blade into a feed channel of the automaticfilling and bagging machine; reserving (430) from the feed channel apreselected bolus volume of grinding composition; preparing (440) areceiver from the roll of laminated plastic for the bolus volume havinga preselected width and a preselected length; dispensing (450) the bolusvolume of the grinding composition into the receiver, and enwrapping(460) the bolus volume by sealing the bolus volume in the receiver suchthat one of a grinding packet or a grinding sheet is formed.

A grinding sheet can be packaged in a manner similar to theaforementioned process to produce a sealed package. Alternatively, agrinding sheet may be packed in a non-sealed package, or an unsealed butsealable package. The grinding sheets can be separated from each otherwith the environment friendly materials such as common paper, releasepaper, plastic film paper, powders, etc.

Each of Example Formulations 1-5 of grinding composition may be used tomake grinding apparatus 200, although each of the Example Formulationsis meant to be illustrative and non-limiting.

Example Formulation 1

Example Formulation 1 may be formed by combining the constituentsdescribed in TABLE 2, using Example Process II, above.

TABLE 2 Grinding Composition Example Formulation I Am't (% w/w)Constituent Material Approx. Grinding Powder grinding powder of 55% w/w natural diamond Thickening Agent white oil 35% w/w  Antirust Powderaluminum distearate 5% w/w Antiwear Powder complex sodium-calcium 2% w/wbased grease soap Antistatic Powder glycerol monostearate 2% w/wAntioxidation Powder dibutylated hydroxytoluene 1% w/w

Example Formulation 2

Example Formulation 2 may be formed by combining the constituentsdescribed in TABLE 3, using Example Process I, above.

TABLE 3 Grinding Composition Example Formulation 2 Am't (% w/w)Constituent Material Approx. Grinding Powder grinding powder of 57% w/w natural diamond Thickening Agent stearine wax 35% w/w  Antirust Powderaluminium distearate 5% w/w Antiwear Powder complex sodium-calcium 2%w/w based grease soap Antistatic Powder glycerol monostearate 2% w/wAntioxidation Powder dibutylated hydroxytoluene 1% w/w

Example Formulation 3

Example Formulation 3 may be formed by combining the constituentsdescribed in TABLE 4, using Example Process II, above.

TABLE 4 Grinding Composition Example Formulation 3 Am't (% w/w)Constituent Material Approx. Grinding Powder grinding powder of 51% w/w natural micron quartz Thickening Agent vegetable oil 20% w/w  AntirustPowder aluminum distearate 15% w/w  Antiwear Powder complexsodium-calcium 6% w/w based grease soap Antistatic Powder glycerolmonostearate 6% w/w Antioxidation Powder dibutylated hydroxytoluene 2%w/w

Example Formulation 4

Example Formulation 4 may be formed by combining the constituentsdescribed in TABLE 5, using Example Process II, above.

TABLE 5 Grinding Composition Example Formulation 4 Am't (% w/w)Constituent Material Approx. Grinding Powder grinding powder of 65% w/w natural micron quartz Thickening Agent vegetable oil 5% w/w AntirustPowder aluminium distearate 15% w/w  Antiwear Powder complexsodium-calcium 6% w/w based grease soap Antistatic Powder glycerolmonostearate 6% w/w Antioxidation Powder dibutylated hydroxytoluene 3%w/w

Example Formulation 5

Example Formulation 5 may be formed by combining the constituentsdescribed in TABLE 6, using Example Process I, above.

TABLE 5 Grinding Composition Example Formulation 4 Am't (% w/w)Constituent Material Approx. Grinding Powder grinding powder of 64% w/w natural micron quartz Thickening Agent stearine wax 32% w/w  AntirustPowder aluminium distearate 1% w/w Antiwear Powder microcrystalline waxin stearine wax 1% w/w Antistatic Powder glycerol monostearate 1% w/wAntioxidation Powder dibutylated hydroxytoluene 1% w/w

A grinding packet for sharpening a paper shredder blade, according tothe teachings herein, is formed to be easy to use, and can be directlyinserted into the paper feed opening of a paper shredder. Similar to theshredding process for paper, when the rotating blade of the papershredder cuts the grinding packet, the sealed bag is cut open. Whenopened, the grinding packet contents are released, at least in part,onto the paper shredder blades. According to the pressure principle, thegrinding powder released from the sealed bag grinds at both sides of arotating shredder blade, thereby sharpening it. Further, an antirustprotection coating film is formed by a functional antirust additivewhich may be included in the grinding composition. Similarly, anantioxidation additive or antistatic additive, or both, which may beincluded in the grinding composition, can enhance the respectiveantioxidation and antistatic properties of the paper shredder blade.Once through the paper shredder blades, the shredded grinding packet canbe disposed in the shredder waste bin. As will be understood by anordinary artisan, functional additives included within the grindingpacket also can provide the function of paper shredder maintenance apartfrom grinding and sharpening the paper shredder blade.

In a similar way, a grinding sheet for sharpening a paper shredderblade, according to the teachings herein, may be employed simply byinserting at least one grinding sheet into a paper shredder feedopening, as one would feed a sheet of ordinary paper to the shredder. Asthe blades of the shredder cut apart the grinding sheet, the grindingconstituent can grind and sharpen a paper shredder blade, whilefunctional additives perform maintenance functions on the shredder blademechanism.

The embodiments of the present invention disclosed herein are intendedto be illustrative only, and are not intended to limit the scope of theinvention. It should be understood by those skilled in the art thatvarious modifications and adaptations of the prevent invention as wellas alternative embodiments of the prevent invention may be contemplatedor foreseeable. It is to be understood that the present invention is notlimited to the sole embodiments described above, but encompasses any andall embodiments within the scope of the following claims.

1. A process for preparing a grinding apparatus, comprising: shift positioning a roll of plastic film at an automatic filling machine for making bags, preparing a grinding composition by selecting a selected grinding powder in a concentration of between about 51% w/w to about 65% w/w, selecting a selected thickening agent in a concentration of between about 5% w/w to about 35% w/w, selecting a selected additive in a concentration of between about 3% w/w to about 30% w/w, and intermixing the selected grinding powder, the selected thickening agent, and the selected additive; feeding the grinding composition into a feed channel of the automatic filling machine, forming a volumetric bolus of the grinding composition sized to form a grinding packet; forming a plastic bag from the roll of plastic film sized to enwrap the volumetric bolus of grinding composition; enwrapping the volumetric bolus of grinding composition with the plastic bag by the automatic filling machine; sealing the plastic bag containing the volumetric bolus of grinding composition by the automatic filling machine such that grinding packet is formed thereby, wherein the volumetric bolus in the grinding packet is representative of an efficacious amount of grinding composition for sharpening a paper shredder blade.
 2. The process for preparing a grinding apparatus, according to claim 1, further comprising the plastic film is a polypropylene plastic film.
 3. The process for preparing a grinding apparatus, according to claim 1, further comprising: imposing an image on one of the roll of plastic film or the plastic bag, wherein the image is one of a character, a picture, or a symbol.
 4. The process for preparing a grinding apparatus, according to claim 1, further comprising: prior to enwrapping, imposing the image by single color printing or imposing the image by chromatographing. 